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Diffstat (limited to 'net/mac80211/mesh.h')
| -rw-r--r-- | net/mac80211/mesh.h | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h new file mode 100644 index 000000000000..8ff46ea0f1d7 --- /dev/null +++ b/net/mac80211/mesh.h @@ -0,0 +1,300 @@ +/* + * Copyright (c) 2008 open80211s Ltd. + * Authors: Luis Carlos Cobo <luisca@cozybit.com> + * Javier Cardona <javier@cozybit.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef IEEE80211S_H +#define IEEE80211S_H + +#include <linux/types.h> +#include <linux/jhash.h> +#include "ieee80211_i.h" + + +/* Data structures */ + +/** + * enum mesh_path_flags - mac80211 mesh path flags + * + * + * + * @MESH_PATH_ACTIVE: the mesh path is can be used for forwarding + * @MESH_PATH_RESOLVED: the discovery process is running for this mesh path + * @MESH_PATH_DSN_VALID: the mesh path contains a valid destination sequence + * number + * @MESH_PATH_FIXED: the mesh path has been manually set and should not be + * modified + * @MESH_PATH_RESOLVED: the mesh path can has been resolved + * + * MESH_PATH_RESOLVED and MESH_PATH_DELETE are used by the mesh path timer to + * decide when to stop or cancel the mesh path discovery. + */ +enum mesh_path_flags { + MESH_PATH_ACTIVE = BIT(0), + MESH_PATH_RESOLVING = BIT(1), + MESH_PATH_DSN_VALID = BIT(2), + MESH_PATH_FIXED = BIT(3), + MESH_PATH_RESOLVED = BIT(4), +}; + +/** + * struct mesh_path - mac80211 mesh path structure + * + * @dst: mesh path destination mac address + * @dev: mesh path device + * @next_hop: mesh neighbor to which frames for this destination will be + * forwarded + * @timer: mesh path discovery timer + * @frame_queue: pending queue for frames sent to this destination while the + * path is unresolved + * @dsn: destination sequence number of the destination + * @metric: current metric to this destination + * @hop_count: hops to destination + * @exp_time: in jiffies, when the path will expire or when it expired + * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery + * retry + * @discovery_retries: number of discovery retries + * @flags: mesh path flags, as specified on &enum mesh_path_flags + * @state_lock: mesh pat state lock + * + * + * The combination of dst and dev is unique in the mesh path table. Since the + * next_hop STA is only protected by RCU as well, deleting the STA must also + * remove/substitute the mesh_path structure and wait until that is no longer + * reachable before destroying the STA completely. + */ +struct mesh_path { + u8 dst[ETH_ALEN]; + struct net_device *dev; + struct sta_info *next_hop; + struct timer_list timer; + struct sk_buff_head frame_queue; + struct rcu_head rcu; + u32 dsn; + u32 metric; + u8 hop_count; + unsigned long exp_time; + u32 discovery_timeout; + u8 discovery_retries; + enum mesh_path_flags flags; + spinlock_t state_lock; +}; + +/** + * struct mesh_table + * + * @hash_buckets: array of hash buckets of the table + * @hashwlock: array of locks to protect write operations, one per bucket + * @hash_mask: 2^size_order - 1, used to compute hash idx + * @hash_rnd: random value used for hash computations + * @entries: number of entries in the table + * @free_node: function to free nodes of the table + * @copy_node: fuction to copy nodes of the table + * @size_order: determines size of the table, there will be 2^size_order hash + * buckets + * @mean_chain_len: maximum average length for the hash buckets' list, if it is + * reached, the table will grow + */ +struct mesh_table { + /* Number of buckets will be 2^N */ + struct hlist_head *hash_buckets; + spinlock_t *hashwlock; /* One per bucket, for add/del */ + unsigned int hash_mask; /* (2^size_order) - 1 */ + __u32 hash_rnd; /* Used for hash generation */ + atomic_t entries; /* Up to MAX_MESH_NEIGHBOURS */ + void (*free_node) (struct hlist_node *p, bool free_leafs); + void (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl); + int size_order; + int mean_chain_len; +}; + +/* Recent multicast cache */ +/* RMC_BUCKETS must be a power of 2, maximum 256 */ +#define RMC_BUCKETS 256 +#define RMC_QUEUE_MAX_LEN 4 +#define RMC_TIMEOUT (3 * HZ) + +/** + * struct rmc_entry - entry in the Recent Multicast Cache + * + * @seqnum: mesh sequence number of the frame + * @exp_time: expiration time of the entry, in jiffies + * @sa: source address of the frame + * + * The Recent Multicast Cache keeps track of the latest multicast frames that + * have been received by a mesh interface and discards received multicast frames + * that are found in the cache. + */ +struct rmc_entry { + struct list_head list; + u32 seqnum; + unsigned long exp_time; + u8 sa[ETH_ALEN]; +}; + +struct mesh_rmc { + struct rmc_entry bucket[RMC_BUCKETS]; + u8 idx_mask; +}; + + +/* Mesh IEs constants */ +#define MESH_CFG_LEN 19 + +/* + * MESH_CFG_COMP_LEN Includes: + * - Active path selection protocol ID. + * - Active path selection metric ID. + * - Congestion control mode identifier. + * - Channel precedence. + * Does not include mesh capabilities, which may vary across nodes in the same + * mesh + */ +#define MESH_CFG_CMP_LEN 17 + +/* + * Components offset within the mesh configuration IE + */ +#define PP_OFFSET 1 /* Path Selection Protocol */ +#define PM_OFFSET 5 /* Path Selection Metric */ +#define CC_OFFSET 9 /* Congestion Control Mode */ +#define CP_OFFSET 13 /* Channel Precedence */ +#define CAPAB_OFFSET 17 /* Mesh Capabilities */ + + +/* Default values, timeouts in ms */ +#define MESH_TTL 5 +#define MESH_MAX_RETR 3 +#define MESH_RET_T 100 +#define MESH_CONF_T 100 +#define MESH_HOLD_T 100 + +#define MESH_PATH_TIMEOUT 5000 +/* Minimum interval between two consecutive PREQs originated by the same + * interface + */ +#define MESH_PREQ_MIN_INT 10 +#define MESH_DIAM_TRAVERSAL_TIME 50 +/* Paths will be refreshed if they are closer than PATH_REFRESH_TIME to their + * expiration + */ +#define MESH_PATH_REFRESH_TIME 1000 +#define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME) + +#define MESH_MAX_PREQ_RETRIES 4 +#define MESH_PATH_EXPIRE (600 * HZ) + +/* Default maximum number of established plinks per interface */ +#define MESH_MAX_ESTAB_PLINKS 32 + +/* Default maximum number of plinks per interface */ +#define MESH_MAX_PLINKS 256 + +/* Maximum number of paths per interface */ +#define MESH_MAX_MPATHS 1024 + +/* Pending ANA approval */ +#define PLINK_CATEGORY 30 +#define MESH_PATH_SEL_CATEGORY 32 + +/* Mesh Header Flags */ +#define IEEE80211S_FLAGS_AE 0x3 + +/* Public interfaces */ +/* Various */ +u8 mesh_id_hash(u8 *mesh_id, int mesh_id_len); +int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr); +int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr, + struct ieee80211_sub_if_data *sdata); +int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr, + struct net_device *dev); +bool mesh_matches_local(struct ieee802_11_elems *ie, struct net_device *dev); +void mesh_ids_set_default(struct ieee80211_if_sta *sta); +void mesh_mgmt_ies_add(struct sk_buff *skb, struct net_device *dev); +void mesh_rmc_free(struct net_device *dev); +int mesh_rmc_init(struct net_device *dev); +void ieee80211s_init(void); +void ieee80211s_stop(void); +void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata); + +/* Mesh paths */ +int mesh_nexthop_lookup(u8 *next_hop, struct sk_buff *skb, + struct net_device *dev); +void mesh_path_start_discovery(struct net_device *dev); +struct mesh_path *mesh_path_lookup(u8 *dst, struct net_device *dev); +struct mesh_path *mesh_path_lookup_by_idx(int idx, struct net_device *dev); +void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop); +void mesh_path_expire(struct net_device *dev); +void mesh_path_flush(struct net_device *dev); +void mesh_rx_path_sel_frame(struct net_device *dev, struct ieee80211_mgmt *mgmt, + size_t len); +int mesh_path_add(u8 *dst, struct net_device *dev); +/* Mesh plinks */ +void mesh_neighbour_update(u8 *hw_addr, u64 rates, struct net_device *dev, + bool add); +bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie, + struct net_device *dev); +void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata); +void mesh_plink_broken(struct sta_info *sta); +void mesh_plink_deactivate(struct sta_info *sta); +int mesh_plink_open(struct sta_info *sta); +int mesh_plink_close(struct sta_info *sta); +void mesh_plink_block(struct sta_info *sta); +void mesh_rx_plink_frame(struct net_device *dev, struct ieee80211_mgmt *mgmt, + size_t len, struct ieee80211_rx_status *rx_status); + +/* Private interfaces */ +/* Mesh tables */ +struct mesh_table *mesh_table_alloc(int size_order); +void mesh_table_free(struct mesh_table *tbl, bool free_leafs); +struct mesh_table *mesh_table_grow(struct mesh_table *tbl); +u32 mesh_table_hash(u8 *addr, struct net_device *dev, struct mesh_table *tbl); +/* Mesh paths */ +int mesh_path_error_tx(u8 *dest, __le32 dest_dsn, u8 *ra, + struct net_device *dev); +void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta); +void mesh_path_flush_pending(struct mesh_path *mpath); +void mesh_path_tx_pending(struct mesh_path *mpath); +int mesh_pathtbl_init(void); +void mesh_pathtbl_unregister(void); +int mesh_path_del(u8 *addr, struct net_device *dev); +void mesh_path_timer(unsigned long data); +void mesh_path_flush_by_nexthop(struct sta_info *sta); +void mesh_path_discard_frame(struct sk_buff *skb, struct net_device *dev); + +#ifdef CONFIG_MAC80211_MESH +extern int mesh_allocated; + +static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata) +{ + return sdata->u.sta.mshcfg.dot11MeshMaxPeerLinks - + atomic_read(&sdata->u.sta.mshstats.estab_plinks); +} + +static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata) +{ + return (min_t(long, mesh_plink_free_count(sdata), + MESH_MAX_PLINKS - sdata->local->num_sta)) > 0; +} + +static inline void mesh_path_activate(struct mesh_path *mpath) +{ + mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED; +} + +#define for_each_mesh_entry(x, p, node, i) \ + for (i = 0; i <= x->hash_mask; i++) \ + hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list) + +#else +#define mesh_allocated 0 +#endif + +#define MESH_PREQ(skb) (skb->cb + 30) + +#endif /* IEEE80211S_H */ |